1. Field of the Invention
The present invention relates to a vertical adjustment device for adjusting the height of a headrest used in a vehicle seat, and, more particularly, to a headrest vertical adjustment device which is capable of adjusting the height of the headrest while supporting, from right and left, a headrest body to be mounted to an automotive seat.
2. Description of the Prior Art
In a conventional vehicle seat headrest vertical adjustment device of this type, an inner slide is vertically slidably mounted internally of right and left outer slides fixed to an arm projected upwardly from a seat back and spaced therefrom, and a stopper is attached through a screw to the lower ends of the outer slides to prevent the above-mentioned inner slide from slipping off downwardly.
However, in the conventional device, there are several problems to be solved. In other words, since the inner slide as well as the stopper secured by means of the screw are formed of metal, respectively, when the inner slide is brought into abutment with the stopper, a metallic shock sound is generated to hurt the feelings of an occupant of the seat. Also, since the outer slides are mounted to a location above the seat back by means of the above-mentioned arm, the screw or the like for the stopper is exposed from the lower portions of the outer slides, impairing the appearance of the headrest. Further, since the arm is welded substantially to the central portions of the outer slides in the vertical direction thereof and the upper ends and outer side surfaces of the arm and outer slides are covered with a flexible cover, when a hard thing happens to hit the cover on the upper ends of the outer slides, then the upper ends of the outer slides provide edges to break the cover, so that the outer slides are exposed and the exposed outer slides may give damage to the seat occupant.